diff --git a/conf/modules/gps_ublox.xml b/conf/modules/gps_ublox.xml
index 8efe27fd7e..1f293e7d8b 100644
--- a/conf/modules/gps_ublox.xml
+++ b/conf/modules/gps_ublox.xml
@@ -41,6 +41,7 @@
     </raw>
   </makefile>
   <makefile target="sim">
+    <file name="gps.c" dir="subsystems"/>
     <file name="gps_sim.c" dir="subsystems/gps"/>
     <define name="USE_GPS"/>
     <raw>